Also worth noting -- when the airbag light is flashing, it is more likely that they will go off unexpectedly than that they will not work in a crash. I got that bit of wisdom from a Ford tech back when a buddy of mine's 94 GT was constantly flashing the airbag light. He had it fixed four or five times under warranty but it would keep coming back. Turns out the Ford tech was wrong in that case, though -- when he did wreck the car, the airbags activated about 1 second too late (can you say, OUCH).
Anyways. Count the flashes, then search online for the code or just run by the Ford dealer and ask them to look it up for you. I bet it's a loose connection somewhere.
Dave